Vacuum extractor



H. W. BIRCH VACUUM EXTRACTOR Jan. 3, 1939.

Filed May 1, 1936 & MW r 4 1 O A Mc eh v M mm M 1 T a Hm/ mama Jan. 3, 1939 vum'ran STATES PATENT OFFICE 2.142.111 vacuum nx'raacroa mm w. Birch, Belmont, Mass.

Application May 1, 1938, Serial No. 77,362

Claims.

Thisinvention relates to vacuum extractors for extracting liquid from cloth or other web material, and particularly to vacuum extractors of that type comprising a vacuum chamber hav- 5 ing one or more slots .or other openings over which the web of cloth is fed or drawn.

The effectiveness of vacuum extractors of this type depends upon the relation between the thickness or porosity of the cloth, the width of the slot and the degree of vacuum within the vacuum chamber. With the same degree of vacuum in the vacuum chamber a wider slot may be more desirable where the cloth being treated is heavy or thick than when the cloth is light in weight and relatively thin, but the width of the slot which is most effective for cloth of any particular weight and character depends also upon the degree of vacuum within the vacuum chamber. It is, therefore, desirable to provide vacuum extractors of this type with means by which the width of the slot can be varied so as to obtain a slot of the width which is most eifectivevfor the particular cloth which is being treated.

It is one of the objects of my invention to provide novel means for thus adjusting the width of the slot of the vacuum chamber.

A further object of the invention is to provide improvements by which the adjustment of the width of the slot can be eifected while the machine so is in operation or without removing the cloth from the machine.

Still a further object of the invention is to provide a novel construction by which the means for adjusting the width of the slot is responsive 35 to the degree of vacuum in the vacuum chamber.

A further object of the invention is to provide a novel construction by which the vacuum chamber, when formed from a slotted tube, is reinforced so as to overcome any tendency of the slot 40 to close up due to vacuum conditions within the tube.

Other objects of the invention are to provide various improvements in vacuum extractors which will be more fully hereinafter set forth.

as In the drawing wherein I have illustrated some In the drawing I indicates the vacuum chamber having the slot 2 over which the cloth or other web material 3 to be treated is passed. As will be understood by those skilled in the art the vacuum within the chamber i operates through 5 the slot 2 to withdraw liquid from the cloth as it passes over said slot.

The vacuum chamber may be made in any suitable way. One convenient way of providing a vacuumchamber is to employ a tube 4 which is slotted along its length and which is connected at one or both ends to a suction apparatus by suitable pipe connections 5, the interior of the tube 4 consituting the vacuum chamber. I have shown this vacuum tube 4 as supported in brackets or supports 6 carried by a suitable supporting frame i.

In vacuum extractors of this type the vacuum chamber is usually of suihcient length to accommodate cloth of any commercial width and where the vacuum chamber is made from a tube of this length a vacuum of high degree, say twenty inches or so, would tend to cause the tube to collapse and thereby close up the slot especially at the center portion 'of the tube.

To prevent this I propose to reinforce the tube along itsslength by brazing or securing thereto in any suitable way two reinforcing bars 8, one either side of the slot in the tube; these bars being stiff enough to prevent the tendency of the tube to collapse due to the vacuum therein.

The walls of the slot 2 are provided by two other bars 9 and ill which are shown as having the rounded surface ll over which the cloth passes, and which, therefore, may be termed cloth-supporting bars". These bars 9 and I0 thus constitute the lips of the slot opening 2. These lip-forming or cloth-supporting bars 9 and iii are mounted on the reinforcing bars 8 and one or both of the cloth-supporting bars 9 and [0 are made adjustable to provide for varying the width of the slot 2.

In the embodiment of the invention herein illustrated the cloth-supporting bar 9 is rigidly being held in position by retaining screws I 3 which are screw-threaded into the bar 3 and operate in slots I4 formed in the lip member II. The adjustable cloth-supportingmember It has arms I! extending therefrom which are pivotally connected to ears I3 rigid with collars I! which are fast on a rock shaft I3 that is journalled in suitable journals I 3 carried by the vacuum tube 4.

Means are provided for rocking the shaft I I, and from the above it will be obvious that such rocking movement will be transmitted through the ears I6 and arms I to the cloth-supporting member III, thereby moving said member toward and from the companion member 3 and thus varying the width of the slot 2.

While various devices for rocking the shaft Il may be employed I have herein shown said shaft as having rigid therewith a curved arm 23, the end 2I of which extends underneath the vacuum tube 4 and is provided with a horizontal slot 22 in which is received a pin 23 that is screw-threaded to an adjusting screw 24. This adjusting .screw 24, whi'cliis provided with a hand-wheel 25 by which it may be manipulated, is mounted for turning movement in a yoke member 23 that is secured to the vacuum tube 4, said ad-v justing screw 24 being held from vertical movement in said yoke but being free to turn about its axis. The stem of the screw 24 is shown as having two collars 2I thereon which are situated either side of the bridge member 23 of the yoke, said collars holding the screw from movement in the direction of its axis. The turning of the adjusting screw 24 will raise or lower the pin member 23 which operates in the slot 22, and such vertical movement of the pin member 23 will cause the arm 20 to swing about the axis of the shaft I8, thereby turning said shaft and effecting the adjustment of the lip member ii. The arm 20 is shown as secured to one end of the rock shaft I8 and the adjusting screw 24 is, therefore, in a position in which it may be manipulated without removing the cloth from the machine or even while the cloth is being fed through the machine.

The device above described provides means for manually adjusting the width of the slot. In Fig. 4 I have illustrated an embodiment of the invention wherein the adjustment of the width of the slot is accomplished automatically and is controlled by the degree of vacuum in the vacuum chamber I. In this embodiment of the invention the cloth-supporting member III is connected by links 23 to three-armed members fast on the rock shaft 3i, the latter being journalled in suitable bearings 32 .carried by the vacuum tube 4. One arm 33 of each three-armed member 30 is connected to the rod 34 of a plunger 35 operating in a cylinder 36 which is secured to the vacuum tube 4 and which communicates at its inner end with the vacuum chamber I. The arm 31 of each three-armed member preferably has a weight 38 secured thereto.

The vacuum in the vacuum chamber I acts on the plungers 35 and tends to move them inwardly, which movement would move the lip member Ill outwardly and open the slot. The weights 38, on the other hand, tend to turn the rock shaft 3| in a direction to close the slot 2. By properly adjusting the weights 38 they will just balance the action of the vacuum in the vacuum chamber I so as to hold the slot 2 at its required width. With this construction any increase in the vacuum will move the plungers 35 inwardly, thereby opening the slot to allow more air to pass into the vacuum chamber which will cut down the vacuum andthe weight 33- is lessened and the weights 33 tend to move the lip-forming member III inwardly, thereby closing the slot which will result in building up the vacuum again. With this arrangement, therefore, the vacuum will be maintained automatically at the desired point within the vacuum chamber.

The degree of vacuum existing in the vacuum chamber I may be stated in terms of pressure, since a vacuum condition indicates a pressure less than atmospheric pressure. Hence, the device illustrated in Fig. 4 comprises means responsive to pressure changes in the vacuum chamber to control the width of the slot.

While I have illustrated some embodiments of the invention I do not wish to be limited to the constructional details shown as these may be varied in various ways without departing from the spirit of the invention.

I claim:

1. A vacuum extractor comprising a vacuum chamber having a slot over which the cloth to be treated is passed, and means responsive to pressure changes in the chamber to vary the width of the slot.

2. A vacuum extractor comprising a vacuum chamber open at one side, two cloth-supporting bars mounted on said chamber at opposite sides of the opening therein and forming between them a slot over which the cloth to be treated passes, a rock shaft supported on the vacuum chamber, means to rock said shaft, and a connection between said shaft and one of said bars by which said bar is moved toward and from the other bar to adjust the width of the slot.

3. A vacuum extractor comprising a vacuum chamber open at one side, two cloth-supporting bars mounted on said chamber at opposite sides of the opening therein and forming between them a slot over which the cloth to be treated passes, a rock shaft supported on the vacuum chamber, a connection between said rock shaft and one of the bars by which rocking movement of the rock shaft moves said bar toward and from the other bar to vary the width of the slot, and means responsive to changes in pressure in the vacuum chamber to turn the rock shaft.

4. A vacuum extractor comprising a vacuum chamber open at one side, two cloth-supporting bars mounted on said chamber at opposite sides of the opening therein and forming between them a slot over which the cloth to be treated passes, one of the bars being movable relative to the other and tothe chamber to vary the width of the slot, and means responsive to changes in pressure in the vacuum chamber to move said movable bar.

5. A vacuum extractor comprising a vacuum chamber opening at one side, two cloth-support HAROLD w. BIRCH. 

